1. Field of the Invention
This invention relates to an office machine, and more particularly to a paper feeding apparatus mounted on an office machine.
2. Description of the Related Art
Referring to FIG. 1, a conventional paper feeding apparatus includes a power driven driving shaft 1, a housing 2 sleeved rotatably on the driving shaft 1, a pickup shaft 3 disposed rotatably on the housing 2 and parallel to the driving shaft 1, an idle wheel 4 disposed between the driving shaft 1 and the pickup shaft 3, and a coiled compression spring 5. The driving shaft 1 includes a rear paper-feeding roller 101, and a first gear 102 connected coaxially and fixedly to the rear paper-feeding roller 101. The housing 2 has a connecting end portion 201 sleeved rotatably on the driving shaft 1, a free end portion 202 opposite to the connecting end portion 201, and an intermediate portion 203 interconnecting the connecting end portion 201 and the free end portion 202. The pickup shaft 3 is disposed rotatably on the free end portion 202, and includes a front paper-feeding roller 301 aligned with the rear paper-feeding roller 101, and a second gear 302 connected coaxially and fixedly to the front paper-feeding roller 301. The spring 5 is sleeved on the driving shaft 1 between a wall of the housing 2 and the rear paper-feeding roller 101.
Due to the pushing force of the spring 5 toward the housing 2 and the rear paper-feeding roller 101, when the driving shaft 1 is rotated, the housing 2 pivots about the driving shaft 1. As such, the housing 2 is pivotable between a first position whereat a paper loading operation can be performed such that a stack of papers can be placed onto a paper-supporting member (not shown), and a second position whereat a paper pickup operation can be performed such that one sheet of the stacked papers can be picked up by the paper feeding apparatus.
Since the spring 5 is sleeved on the driving shaft 1, the moment arm associated with the pushing force of the spring 6 applied to the driving shaft 1 and the housing 2 for pivoting the housing 2 about the driving shaft 1 is short. This necessitates the use of a large amount of power for rotating an assembly of the driving shaft 1 and the housing 2. Furthermore, it is difficult to mount the spring 5 between the driving shaft 1 and the housing 2.